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tanzanite

(Encyclopedia)tanzanite tănzănˈīt [key], beautiful gemstone discovered in 1967 in the Umba Valley near the Usambara Mts. in Tanzania, a precious variety of the mineral zoisite, a calcium aluminum silicate. Zois...

filigree

(Encyclopedia)filigree fĭlˈĭgrē [key], ornamental work of fine gold or silver wire, often wrought into an openwork design and joined with matching solder and borax under the flame of the blowpipe. Filigree is u...

rood

(Encyclopedia)rood ro͞od [key], crucifix mounted above the entrance to the chancel and flanked by large figures of the Virgin and St. John, an almost invariable feature in the 14th- and 15th-century European churc...

dolomite

(Encyclopedia)dolomite dōˈləmītˌ, dŏlˈə– [key]. 1 Mineral, calcium magnesium carbonate, CaMg (CO3)2. It is commonly crystalline and is white, gray, brown, or reddish in color with a vitreous to pearly lus...

mercury poisoning

(Encyclopedia)mercury poisoning, tissue damage resulting from exposure to more than trace amounts of the element mercury or its compounds. Elemental mercury (the silver liquid familiar from thermometers) is the mos...

molecular weight

(Encyclopedia)molecular weight, weight of a molecule of a substance expressed in atomic mass units (amu). The molecular weight may be calculated from the molecular formula of the substance; it is the sum of the ato...

Heimlich maneuver

(Encyclopedia)Heimlich maneuver, emergency procedure used to treat choking victims whose airway is obstructed by food or another substance. It forces air from the lungs through the windpipe, pushing the obstruction...

blister beetle

(Encyclopedia)blister beetle, common name for certain soft-bodied, usually black or brown, mostly elongate and cylindrical beetles belonging to the family Meloidae. Blister beetles are common insects found feeding ...

sphalerite

(Encyclopedia)sphalerite sfălˈərīt, sfāˈ– [key], mineral composed of zinc sulfide, usually containing some iron and a little cadmium. It occurs in crystals of the isometric system but more generally in clea...

sand

(Encyclopedia)sand, rock material occurring in the form of loose, rounded or angular grains, varying in size from .06 mm to 2 mm in diameter, the particles being smaller than those of gravel and larger than those o...